I don’t have a V4 so I can’t confirm, but @Spartan on the thread below mentioned V4 doesn’t have this issue. However, there’s no guarantee this won’t happen for future firmware updates.
Please note if you power cycle or experience power outage while the internet is down, then the camera will start recording based on the firmware build date. If you know the specific firmware build date then technically you can view it on the Wyze App. This is true for all Wyze wired cameras as far as I know.
In regards to your issue manually flashing Cam V3, make sure you are using 32GB microSD (formatted in FAT32) or smaller. You can use this sdcard.org program here. Make sure you are holding on the setup button before plugging the power back in. I would continue to hold on the setup button for 10 seconds to be sure after plugging in the power.